This invention is in the general field of devices and methods for authenticating sample compositions.
Authenticating and monitoring products to discriminate between very similar complex mixtures is useful for various reasons. For example, the use of counterfeit substances (e.g., misbranded material from a competitor or misformulated material from a licensee/franchisee) should be detected to preserve the integrity of a brand. Also, low quality substances (e.g., diluted or misformulated product) should be quickly and conveniently detected for appropriate correction.
Commonly assigned U.S. Pat. No. 5,753,511, which is herein incorporated by reference in its entirety, discloses an automated method of developing a database to store information for xe2x80x9cfingerprintxe2x80x9d-type analysis of products (even as to product lot numbers and batch). The automated analysis is a method of evaluating and discriminating products, even within a narrow field or industry, competing and otherwise, e.g., to establish authenticity or point of origin of the product. The invention therein relates to an automated method for identifying key ingredients and/or the relative amounts of key ingredients in products using light-emissive compounds.
The laboratory equipment used to authenticate the sample referred to in ""511 is not easily and cost effectively transported. Thus, determining product authenticity on site, either at manufacturing points or at distribution points, is impractical. With regard to distribution of counterfeit substances or production of misformulated material from a licenser/franchiser, the brand owner may not desirably spontaneously check product authenticity on site.
Furthermore, a processing plant, for example, may have numerous continuous processes being performed at any given time. It may be desirable to test the product for purity or quality, for example, as the product is being produced. With relatively large, expensive laboratory equipment, this is not possible. As a result, the process must cease, sample product must be sent to a remote site for testing and the process may not resume until the samples have been tested.
According to one aspect of the invention, a portable product authentication device is provided. The device includes a base unit having a flexible conduit and a probe assembly coupled to the flexible conduit. The probe assembly has a light source for irradiating a sample to be authenticated with a predetermined wavelength of light. The device further includes an optical detector for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic. A controller is disposed within the base unit and communicates with the probe assembly for receiving the sample characteristic and comparing the sample characteristic to a fingerprint. In one embodiment, the controller is located at a site remote from the probe assembly and may comprise a database of stored fingerprints. In one embodiment, the light source is a light-emitting diode. In another embodiment, the light source is a fiber optic cable operatively connected to a light-emitting diode. In yet another embodiment, a fiber optic cable is disposed within the probe assembly and is operatively connected to the optical detector for receiving emitted light generated by the sample and transmitting to the optical detector. Alternatively, the optical detector is disposed within the probe assembly.
In an important embodiment, the device includes a receptacle for interchangeably receiving one of a plurality of light sources. Each of the light sources is selected to emit a desired wavelength of light based on a desired sample to be authenticated.
In another embodiment, the device may also include an emission filter for filtering undesired wavelengths of light from the at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light and/or a source filter for filtering undesired wavelengths of light generated from the light source. In yet another embodiment, the probe assembly is adapted to interchangeably receive one of a plurality of emission filters, and/or one of a plurality of source filters. Each emission filter is selected to filter undesired wavelengths of light based on a desired sample to be authenticated and each source filter is selected to filter undesired wavelengths of light based on a selected light source.
In another embodiment, the optical detector detects a quantity of the at least one emitted wavelength of light generated by the sample. Alternatively, the optical detector detects a change in quantity over time of the at least one emitted wavelength of light generated by the sample. The optical detector detects a characteristic of an authentic sample to provide the fingerprint and may perform a plurality of detections on a single sample to be authenticated. The fingerprint may include a range of acceptable fingerprints.
In yet another embodiment, the probe assembly further includes a holder adapted to receive the sample. The probe assembly may include a reflector to reflect light emitted from the light source toward the sample.
In another aspect of the invention, a probe assembly for detecting a characteristic of a sample to be authenticated is provided. The probe assembly includes a hand-held probe body and a light source disposed in the body for irradiating the sample with a predetermined wavelength of light. An optical detector is disposed in the body for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic.
In one embodiment, the light source is a light-emitting diode. In another embodiment, the probe assembly includes a light-emitting diode receptacle formed in the body for interchangeably receiving one of a plurality of light-emitting diodes. Each of the light-emitting diodes is selected to emit a desired wavelength of light based on a desired sample to be authenticated.
In another embodiment, an emission filter disposed in the body for filtering undesired wavelengths of light from the at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light. A source filter may be disposed in the body for filtering undesired wavelengths of light generated from the light source. In an important embodiment, the probe assembly includes an emission filter receptacle formed in the body for interchangeably receiving one of a plurality of emission filters and/or a source filter receptacle formed in the body for interchangeably receiving one of a plurality of source filters. Each emission filter is selected to filter undesired wavelengths of light based on a desired sample to be authenticated and each source filter is selected to filter undesired wavelengths of light based on a selected light source.
In yet another embodiment, the probe assembly further includes a holder adapted to receive the sample. The probe assembly may include a reflector to reflect light emitted from the light source toward the sample.
In yet another aspect of the invention, a kit for detecting a characteristic of a sample to be authenticated is provided. The kit includes a hand-held probe body having a plurality of receptacles and at least one light-emitting diode for irradiating the sample with a predetermined wavelength of light. Each light-emitting diode is adapted for insertion into one of the receptacles and is selected based on a desired wavelength of light to be emitted. Each desired wavelength is based on a desired sample to be authenticated. An optical detector for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light is also provided. The probe body may also include a reflector for reflecting light emitted from the light source toward the sample. In one embodiment, the kit further includes at least one emission filter for filtering undesired wavelengths of light from the at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light and/or at least one source filter for filtering undesired wavelengths of light generated from the light-emitting diode. Each filter is adapted for insertion into one of the receptacles. The kit may further include at least one light-emissive compound. Each light-emissive compound is adapted for reaction with a selected sample to be authenticated.
The kit may further include a holder adapted for insertion into the probe body. The holder is adapted for holding the light-emissive compound and the sample. The kit may also be provided with a carrying case.
In yet another aspect of the invention, a method for detecting a characteristic of a sample to be authenticated using a portable authentication device is disclosed. The device has a probe assembly having a light source for irradiating a sample to be authenticated with a predetermined wavelength of light and an optical detector for detecting at least one emitted wavelength of light generated by the sample in response to the irradiating wavelength of light to provide a sample characteristic. The method includes the steps of detecting background light with the optical detector, adding a light-emissive compound to an authentic product sample to form an authentic sample mixture, irradiating the authentic sample mixture with an irradiating wavelength of light, detecting one of a quantity and a change in quantity over time of light generated by the authentic sample mixture in response to the irradiating wavelength of light to provide a fingerprint, adding a light-emissive compound to a test product sample to form a test sample mixture, irradiating the test sample mixture with an irradiating wavelength of light, detecting one of a quantity and a change in quantity over time of light generated by the test sample mixture in response to the irradiating wavelength of light to provide a test sample characteristic, comparing the test sample characteristic to the fingerprint to determine whether the test sample is authentic.
In an important embodiment, the irradiating step and the detecting step for both the authentic sample mixture and the test sample mixture occurs in close spatial and temporal proximity. In another embodiment, when the test sample is not authentic, the method further includes the step of communicating with a remote computer and reading a stored fingerprint to determine the identity of the test sample.
In another embodiment both a quantity and a change in quantity over time of light generated by the authentic sample mixture may be detected.
In another embodiment, the method further includes the step of communicating with a controller having a database of a plurality of fingerprints. The communication occurs after a determination that the test sample is not authentic based on the comparison and wherein the step of communicating includes the step of comparing the test sample characteristic to the database of fingerprints.
In yet another embodiment, a plurality of detections on one of the authentic sample and test sample is performed.
According to another aspect of the invention, a chip is provided. The chip is a substrate and plurality of different light-emissive compounds attached to a surface of a substrate. The compounds are attached in a manner whereby they can interact with interaction partners, such interaction altering light emission from the light-emissive compounds, versus light emission from the light-emissive compounds absent interaction. Each of the different light-emissive compounds is attached at a location discrete from attachment of all other of the difference light-emissive compounds. The substrate is free of interference with light emission from the light-emissive compound in the presence of the interaction and in the absence of the interaction. In one embodiment, the plurality of compounds is selected from the group consisting of three different light-emissive compounds, four different light-emissive compounds, five different light-emissive compounds, six different light-emissive compounds, seven different light-emissive compounds, eight different light-emissive compounds, and nine different light-emissive compounds. In one important embodiment, the light-emissive compounds are dyes. The chip can define a plurality of microwells. The discrete location of attachment of each of the different light-emissive compounds can be confined to a microwell or several microwells. In a preferred embodiment, the chip has one or more markings for locating the position of each of the light-emissive compounds on the chip and/or for identifying what different light-emissive compounds are on the chip. The light-emissive compounds can be covalently or non-covalently attached to the chip.
In an important embodiment, the different light-emissive compounds in the chip are preselected and are at a preselected concentration to interact with a known standard and create a preselected pattern of light emission when the surface is contacted with the known standard characteristic of the known standard. In this instance, the marking in the chip can identify the chip as specific for the known standard.
According to another aspect of the invention, a method is provided for determining relatedness of a sample to a standard. The method involves providing a sample mixture comprising the sample applied to the surface of any of the chips described above. The sample mixture then is irradiated with a plurality of irradiating wavelengths of light. At least one emitted wavelength of light, but more typically a plurality of such wavelengths, is monitored to establish a sample emission profile. A standard fingerprint characteristic of a standard mixture is provided, the standard mixture comprising the standard applied to the surface of chip, and the standard fingerprint being generated by irradiating the standard mixture with the irradiating wavelengths and monitoring the at least one emitted wavelength in response thereto. The sample emission profile is then compared with the standard fingerprint to determine the relatedness of the sample on the standard. The sample can be applied to the surface of the chip as a microdot. In an important embodiment, the chip comprises microwells containing the light-emissive compounds, and the sample is applied to the surface of the chip as a microdot. In this embodiment, the microdrop can be permitted to spread across the surface of the chip to occupy the microwells, preferably in a manner whereby the sample is contained non-overlapping in discrete microwells once it has spread. A microchip with a wetable surface is particularly desirable in this embodiment.
According to an other aspect of the invention, a kit is provided. The kit is a package which contains a plurality of discrete substrates, each of the substrates containing or having attached thereto an identical set of 3-9 light-emissive compounds. The set is selected to interact with a known standard and create a preselected pattern of light emission when irradiated with at least one wavelength of light in the presence of one interaction. The package also contains instructions indicating that the substrates are for use with a known standard or samples for which the relatedness of the samples to the known standard is to be determined. The substrates can be constructed and arranged for use with the portable product authentication device of the invention.
In another aspect of the invention, a probe assembly for detecting a characteristic of a sample to be authenticated is provided. The probe assembly includes a hand-held probe body, a light source disposed in the body for irradiating the sample with a predetermined wavelength of light, and a plurality of fiber optic cables disposed in the body and communicating with at least one optical detector. The fiber optic cables are adapted and arranged to receive light emitted from a corresponding sample placed on a chip.
Various embodiments of the present invention provide certain advantages and overcome certain drawbacks of the conventional techniques. Not all embodiments of the invention share the same advantages and those that do may not share them under all circumstances. This being said, the present invention provides numerous advantages including the noted advantage of on-site testing.
Further features and advantages of the present invention as well as the structure and operation of various embodiments of the present invention are described in detail below with reference to the accompanying drawings.